Piston ring chamfering machine



April 10,1945. H. M. SCARFF I PISTON RING CHAMFERING MACHINE 4 Sheets-Sheet l v Filed Feb. 14, 1944 Ill Harold N-Scarff B5 April 10,-1945. 'H. M. SCARFF v PISTON RING CHAMFERING MACHINE Filed Feb. '14, 1944 4 Sheets-Sheet 2 \nuenfor {mom M Scarff v/ MLm a Mforncgs April 10, 1945.

H. M. SCARFF PISTON RING CHAMFERING MACHINE Filed Feb. 14, 1944 4 Sheets-Sheet 3 f M a TC M X H, M MA r a 3 pr 10, 1945- H. M. SARFF 2313,3 14

PISTON RING CHAMFERING MACHINE 1 Filed Feb. 14, 1944 4 Sheets-Sheet 4 Patented Apr. w, i945 KISTON RING Q name mama.

Harold M. 'Scarfi,.Muskegon, Mich, assignor to Muskegon Piston Ring Company, -Muskegon, Mich, a corporation of Michigan Application February 14,4944, Serial No. 522,277 Claims. ((31. 77- 3) the rectangular cross section of the ring so that when the ring is closed at its parting, its fiat sides are slightly distorted out of the plane that they would occupy if the ring had a uniform rectangular cross section. This is desirable in piston rings used with internal combustion engines, and the present invention is directed to a machine by means of which the rings may thus be "machined and chamfered at the desired inner corner portion and by means of which very rapid machining and a high quantity production may be attained with a uniformity of product and without employment of.skilled labor.

An understanding of the invention may be had from the following description taken in connection with the accompanying drawings, in which,

Fig. l is an elevation of a. machine embodying my invention, certain parts being broken away for better disclosure.

Fig. 2 is a. fragmentary vertical longitudinal section through the operating mechanism.

Fig. 3 is a fragmentary section, similar to that in Fig. 2, somewhat enlarged and illustrating a different position of the parts than in Fig. 2.

Fig. 4 is a fragmentary section and elevation substantially on the plane of line 13-43 of Fig. 1.

Fig. 5 is a fragmentary end elevation looking and at the lower portion thereof.

Fig. 6 is a transverse verticalsection on th plane of line 8% of Fig. .2 looking in the direction indicated.

Fig. 7 is a sectional detail illustrating the inner chamfer cutv on a piston ring and the machine tool'for obtaining such cut, and

Fig. 8 is a diagramvof wiring circuits used in controlling the machine operation.

Like reference characters refer to like parts in the different figures of the drawings.

Upon the bed I, which is similar to a lathe bed,

a stock 2, analogous to a tail-stock in a lathe, is permanently secured toward one end of the bed,

spaced from which is a fixture 3 likewise permanently secured'to the bed. Spaced a. short distancefrom the fixture 3 is a stock 6, analogous to the head stock of a lathe, which is mounted Y for slidable movement on the lathe bed.

The members: and *3 are fixed with respect to each other and between them a support for the piston rings which are to be machined is deat the machine shown in Fig, 1 from the right tachably carried. The piston ring support com- 7 prises a bar 5, T-shaped in cross section (Fig. 6),

which at one end has an upwardly extending part 6 from which anupper horizontal bar portion 1 extends to each side. A rod 8 is fastened to the part 7' and extends over in substantial parallelism to the bar 5 for a part of its length. Two spaced pins or similar-projections 9 extend from the adjacent side of the stock 2 between which the, part 6 of the ring holding bar may be inserted with the upper portion I resting upon the pins 9 to thereby support the ring holding bar 5 at one end. At the other end a hook memher it connected with the bar extends upwardly and is adapted to detachably connect with a plate I! secured at the a jacent face of the fixture 3 (Fig, 3), entering an opening made in said plate as shown. The handle 8 may be grasped and the ring holding bar removed by lifting it upwardly and disengaging the hook in from the plate H, the flanges of the T bar 5 terminating short of the pin 9 as shown in Fig. 2. On this bar a plurality of piston rings l2 may be suspended as shown in Fig. 6, the end portions of the ring at each side of the gap resting upon the lower flanges of the T-bar 5, and the upwardly extending leg of said bar 5 being locatedv in the gaps between the ends of the rings. With this construction the rings 5 are movable lengthwise of the bar.

The fixture 3 has a horizontal opening therethrough in which a sleeve bushing 53 is secured,

said bushing having an axial opening which at its end toward the piston rings is of larger diameter than at the other end, and progressively decreases in diameter, forming a conical surface as indicated at M fora part of the length of the opening. Accordingly when the piston rings are forced into the bushing I3 they are contracted'and closed at their gaps after they have been forced through the. bushing past the conical interior surface thereof. I

In thestock 2 a rod is is mounted for longitudinal reciprocation, having a head 5 at its inner end adapted to come against the end piston ring iii of the rings suspended from the bar 5;

' and of. course at the upper side of the head IE it is I longitudinally recessed so that it may pass along the recess.

the lower portion of the bar 5 which extends into At its outer end portion the rod It carries a ratchet bar H at its under side, and it is equipped. with a handle [8 near its outer end.

. Spaced brackets l9 (Figs. 2 emai extend outwardly from the member 2 above rod l6 between which is carried a rod 26 A lever 2| is forked at its upper end, the fork having spaced sides 22, through the upper ends of which the rod 26 passes whereby the lever 2| has a pivotal movement about the axis of the rod. A dog 23 is pivotally mounted between its ends on and between the sides 22 of the fork and at one end engages with the teeth of the ratchet bar H. A brake 24 is mounted on the rod and extends inwardly a short distance and has a concave under side to bear against the upper side of the rod i6. A cross bar 25 extends between and is permanently secured at the upper ends of the sides 22 of the fork through which a screw 26 (Fig. 2) passes bearing against the upper side of the brake 24 to adjust its pressure against rod l6. Normally the lever 2| is pulled by the spring 21 in a clockwise direction (Fig. 1); A switch 28 cf the mercury tube type is mounted to turn upon a horizontal axis on one of the brackets l9 having depending from the holder thereof a finger 29 which is engaged by the end of the screw 3|! upon movement of the head l5 and rod IE to an extreme position to the right. The screw 30 is adjustably mounted as shown to thereby control the time of operation of the switch.

A horizontal rod 3| passes through the lower end portion of the lever 2| and is provided adjacent its outer end with a block 32 adjustably mounted on the rod which, on movement oi the rod 3| to the right (Fig. 1) will engage with and swing the lever 2| in a counter-clockwise direction against the force of the spring 21. In doing this the dog 23 engaging with the teeth or the ratchet bar I! will cause a longitudinal movement of the rod l5 and attached head to the right moving the piston rings [2 along thebar and forcing them through the bushing l3. A bracket 33 is connected to and depends from the head stock 4 to which a piston rod 34 is secured together with the rod 3| by suitable couplings as shown (Fig. l). The piston rod enters a horizontal cylinder 35 and is connected with the usual piston.therein (not shown). The cylinder 35 is supported by the bracket 36 extending from the end of the lathe to opposite ends of the cylinder for carrying compressed air. The compressed air is delivered through an inlet pipe 39 (Fig. 5) connecting with a valve housing 40 to which the pipes 31' and 38 are also connected. Change of position of the valve within the valve housing directs the air selectively to either the pipe 31 or 33.

Above the. valve housing 40 is a housing 4| within whih are two solenoid windings (not shown) with the usual armature, the energizing of one solenoid winding opening the valve in one direction and of the other in the opposite direc tion. The control of the passage of current to the windings is by means of two switches, one of which at 42 is acted upon by a bar or finger 43 adjustably mounted, moving with and depending below the head stock 4 and engaging with the switch 42 and closing it upon the movement of the head stock 4 to the right (Fig. 1) the sufficient distance for the bar 43 to operate the switch. The adjustment of. the bar 43 permits a control of the time when the switch is actuated. The other switch controlling the other solenoid will be hereafter described.

'A rotatable shaft 44 is mounted horizontally on and extends through. the head stock 4 at its inner endhaving a cylindrical socket head 45. A. tool carrying head 46 provided with a tapered spindle" to be inserted into the socket car- Pipes 3! and 33 lead An interiorly threaded ring 52 is movably mounted by means of screws 53 at the inner side of the head stock 4 as shown, coiled compression spring 54 around the screws normally tending to move the ring away from the adjacent side of the head stock until stopped by the heads of the screws engaging the bottoms of the recesses in which they are located, as in Fig. 2. An exteriorly threaded sleeve 55 is screwed into the ring 52 and is provided with a flange 56 at its outer end into which sleeve the tool carrying head 46 extends. The interior diameter of the opening through the sleeve 55 is slightly less than the exterior diameter of the rings that are processed when said rings are closed at their partings. The

face of the flange 56 is adapted to come against the outermost ring at the position to which it has been moved in Fig. 2 and move it back until said face engages against the outer face of the bushing I3 as will hereinafter appear in'the description of the machine operation. Cooperating stops 5'! and 56 on the adjacent faces of the head stock 4 and the ring 53 limit the extent to which the springs 54 maybe compressed upon movement-oi the head stock to the left (Fig. 3)

and engagement of the flange 55 against the outer face of the bushing l3.

A second switch 59 is mounted upon and at the upper side of the head stock 4, adapted to be operated by the engagement thereagainst of the end of a screw 66 (Fig. 3) adjustably mounted at the upper end of a bracket 6| secured to the uppenside of the ring 52.- Said switch 56 and also the switches 42 and 28 are interposed in the circuitcontrolling completion of the solenoid windings housed within the housing 4|. In Fig. 8 one wire 52 of the circuit leads to each of said solenoid windings, the other wire 63 has two branches, 54 and 55, which lead one to each of said solenoid windings and it is in said branches 64 and '65 that the switches 42 and 53 are interposed. The switch 28 is interposed in the circuit wire 63 ahead of the branches 64 and 65.

Operation The rings l2'which are who chamfered are loaded on the bar 5 with said bar suspended between the supports 9 and Prior to the load-i ing of the machine with the rings, the rod l6 has I been pulled back manually as far as possible by a grasping of the handle l8 and releasing the dog 23, the end engaging the ratchet bar ll being depressed by lifting the opposite end of the dog: and simultaneously the lever 2| may bepressed against to the right'(Fig. 1) to relieve the brake at 24. After the loading has been com..

pleted the head |5 is brought against the out- ,ermost piston ring |2 by manually moving the rod I5 and the attached head in the opposite direction. The switch 26-, in the position shown -of the-ratchet bar I distance beyond its face as shown in Fig.

' ment of the tool as a sumcient'distance that the ing and the drop downwardly,

upon and suspended I asras'se the pipe" 38, and-the head'stock d with the various parts carried thereby has been moved to the extreme right, in Fig.

the switch 62 at such extreme of position of the head stock 6, the flow of compressed air is reversed and goes through the'pipe 31 to the opposite end of the cylinder, moving the head stock in the opposite direction. The prior movement of the head stock 3 to the right brings the block 82 against the lever 2i, thereby operating the dog against a ratchet tooth l and moving the body of piston rings to a position such that the outermost piston ring in the bushing l3 projects a short 2; and the flange at 56 has been moved back from the face of the bushing. i L

Upon the reversal of direction of movement of the piston rod '36, because of the compressed air entering the outer end or the cylinder '35, the head stock It is moved in a direction toward the fixture 3 and the bushing therein, and the face of the flange 56 is brought against the endof the bushing with the tool carrying head 56 entering into said outermost ring and bringing the-cut ting edge of the tool 48 against the adjacent inner corner of the ring. A continuance of the movement takes place with a compression of the springs M with a' corresponding feeding move desiredchamfer cut is removed from the ring. The outermost projecting ring, as it is shown in Fig. 2, is likewise engaged by the face of the flange 55 so that the outer face of the outermost ring is brought flush with the outer side of the bush-- face of'the'iiange 55, as in Fig. 3,- at the completion of the machining. This forces the body of rings within the bushing back slight distance against the friction of the compressed rings within the bushing and also against the action of the brake .atfit; The end of the dog 23 is back of the tooth on ratchet bar ll with which is was engaged inmoving the rod it to the right a suiflcient distance that 'suchbackward movement of the rings, and 'of course with them the head l5 and the rod I6 is permitted without danger of breakage When the machining of the outer ring has been completed, and the parts have reached the position shown in Fig. 3-switch59 becomes closed,

the compressed air is carried to the opposite end of the cylinder 35, and the head stock 6 and attached parts are retracted and moved to thekposition shown inFig. 2. Simultaneously, through the rod 3! operating the lever 2i the machined ring is pushed outof the bushing so. that it may and the next succeeding ring is moved to the position shown in Fig. 2, immediately afterand almost substantially coincident with which the switch $2, is closed with a conse-' quent return movement of the head stock toward and eventually to the position in Fig. 3 for machining the succeeding piston ring and cutting its chamfer at its inner annular comer. Such cycle of operations is'repeated one after the other until theend of the screw at M engages against the-finger at 28 and movesthe switch 28 to open position, whereupon the machine is stopped in operation otherthan the rotation of .shaft 44 and attached parts by the motor- 51.

This leavesthe machine with thebushing sub-' 'stantially filled with piston rings, and ready to have a succeeding plurality of piston rings placedfrom the bar 5 after having first moved the rod l6 andtheattached head It 3. But as soonas the bar 43 comes to and'closes as far to the left as can be done, so the bar 5 may be loaded substantially the entire length of its 'l-flanges. Such movement of the rod is back releasesthe mercury switch at 28 which automatically moves to its closing position, and the machine is ready to take up, its operation and go through the succeeding series of operative cycles until the :sWitch'ZB is again moved to'circ'uit open position by the screw as engaging against theflnger 29.

All that the attendant of the machine has to do is keep the bar 5 loaded with the proper sizes 'of rings. The machine has adjustments in the screws 3d and 66 and in the connection of the switch operating member 63 and in the adjustable block 32 to take care of various axial widths of rings within prescribed limits. The stops at El and 58' are not essential except perhaps for purposes of safety, as the closing of the switch at 59 will or should take place immediately before said stops come against each other; But in the eventtha't the electrical connections were disturbed or out of order so that closing the switch at 60- did not result in the reversal of movement of the head-stock t, said stop means would imsure against a ontinuation of feeding of the tool 88 into the ring being processed beyond a desired point. Therefore the machine will be and in practice at 6'8 and 5B are not used.

' .The machine described is in practical everyday use. with it a large quantity processing, of the piston. rings to obtain the desired chamfer is attained with uniformity in'product. For different diameters of piston rings, diiierent bushings l3; sleeves 55, tool carrying heads 36 and. pusher heads it may be substituted with of course the necessary adjustment fortiming the closing of the switches and the amount of movement imparted to the rod lt by each swing of the lever 2i fortaking care of the differing axial dimensions of said piston rings,

The invention is exceptionally practical and useful, is defined in the appended claims and is to be considered comprehensive .of all forms of structure coming within their'scope."

I claim: v

1. Means for-supporting a plurality of parted piston rings in side by side contact with each other, means for periodically moving the rings axially a short distance, means for closing the rings at their partings at oneend of the plurality of rings and holding said rings closed, and means forinoving arotating cutter tool toward and away fromthe outer side of the outermost of said closed rings to machine said outermost ring between periodic axial movements of the rings, said tool being moved away from the outermost ring after the machining thereof, whereby the succeeding axial movement of the rings releases the v machined ring from said ring closing and holding means.

2. A bar having a lateral flange at its lower edge at each side thereof on which flanges a plurality of parted piston rings are adapted to bar, a sleeve bushing passing through the flxture, said bushing -having. an opening 'therethrough with conical sides whereby piston rings are contracted and closed at their partings when forced therein, a support for the other end of said bar,

-a plunger slidably mounted through the support having a head to engage against the outer piston ring at one end of aplurality of piston rings carried on said bar, means for intermittently mov- 'is fully operative-even though the'stop be suspended, a fixture supporting one end of the ing said plunger in one direction to force the piston rings through the bushing at intervals with periods of rest between said movements, and means for machining the ring at the other end of the plurality of piston rings while it is held by and in closed position within said bushing, said machined ring being-forced from said bushing and released upon the next succeeding periodic movement imparted to all the rings.

3. A construction containing the elements in combination defined in claim 2, said means for intermittently moving said plunger and head comprising, a slidably mounted actuating rod, means for reciprocating said actuating rod, a lever pivotally mounted on the second mentioned support for said bar, said actuating rod extending adjacent the lever, a block on the actuating rod to engage against and move the lever about its pivot on movement of the actuating rod toward said fixture, a spring connectedto said lever normally acting to move the lever in the opposite direction, a ratchet dog pivotally mounted on said lever, anda ratchet bar secured to and lengthwise of the first mentioned rod with which said dog engages.

4.'A support, a plunger slidably mounted on carry a plurality of parted piston rings between the support and fixture, a head stock located a distance from said fixture, means for moving said head stock toward and away from said fixture,

means connected with said head stock for periodically moving said plunger toward the fixture,

' said support, a fixture spaced from the support,

6. In apparatus as disclosed, means for periodically moving a predetermined quantity of open parted piston rings located side by side in an axial direction, means into and through which the rings are passed to close the rings at their partings, a rotatable tool carrying member, means on which it is rotatably mounted movable to-- ward and away from the outermost closed piston rings in succession to successively machine the rings and a common means for periodically moving the piston rings and for reciprocating the tool carrying means, with the periodic movements of the rings taking place when the tool carrying member is moved away from the rings.

' 7. A construction as in claim 6, in which said common means for moving the piston rings and reciprocating the tool carrier comprises a pneumatic operating cylinder and piston rod reciprocable thereby, means for supplying pneumatic pressure alternately to opposit ends of the cylinder including a movable control valve, electric means for operating said valve including two electric circuits each with a switch therein and means mounted on the tool carrying means for alternately closing said switches to operate said valve to alternately direct pneumatic pressure to opposite ends of the cylinder. 8. In an apparatus as described, a fixed bushing having a tapered opening therethroug'h, and an "outer face adjacent the smaller end of said opening, a cutter head movable toward and away from the outer face of said bushing, a rotatable cutter said movement occurring when the head stock is moved away therefrom, a rotatable shaft mounted on the head stock, means for driving saidshaft, and a machining tool carried by said shaft at its inner end to machine the e'ndmost of the piston rings passing through the opening in the bushing.

5. A construction containing the elements in combination defined in claim 4, and a ring movably mounted on said head stock between it and said fixture around the shaft, spring means normally moving the ring away from the head stock, means to stop the ring at an outer extreme of said movement, and means carried by the ring engageable against the adjacent end of the bushing and partly against the end piston ring therein around the peripheral side portions thereof.

mounted on said cutter head, means for intermittently pushing'rings through the opening in said bushing one at a time, said means pushing the forward face of the forward ring beyond the forward face of the bushing, means for moving said cutter head toward said bushing to an accurate position relative to the: forward ring and means to retract said forward ring to a position whereat its forward face will be accurately located ..relative to the forward face of the bushing.

9. The elements of claim 8 in which said means for retracting the forward ring is carried by said cutter head.

10. The elements of claim 8 in which said means to retract said forward ring is carried by said cutter head and engages the forward face ,of the bushing when effecting the retraction and is yieldable axially of the cutter when it engages the forward face. of the bushing.

HAROLD M. 'SCARFF. 

